Watching the Sacramento mile on
http://www.fanschoice.tv/watch-live/american-flat-track
Joe Kopp rode a couple exhibition laps on a four cylinder two stroke TZ750 Yamaha like the one Kenny Roberts won the Indy mile on back in the '70s. I was at that race - it was crazy. Roberts could gain fifty to a hundred feet on the straightaways, but lose it to the Harleys in the corners. After the race Corky Keener said "I heard that screamin' son-of-a -biatch comin' and knew it was over. Passed Keener and Springsteen as I recall at the finish line for the win. I think there were three of them entered but only Roberts made the main. The cords of the rear tire were showing - one more lap and it may not have finished or worse for King Kenny.
That was a great race: night-time at Indy, wow.